Traction assist means for loading machines and the like

ABSTRACT

A loading machine is disclosed having a main frame, a forward swing frame pivotally mounted on the main frame, a loading bucket assembly supported on the swing frame for movement to pick up and dump loose material onto the swing frame, and traction assist means movable to a ground engaging position in a manner to prevent rearward movement of the loading machine as the bucket assembly is moved forwardly into a pile of loose material and to stabilize the machine as the bucket is raised to a dumping position. The traction assist means is further operative to effect a forward movement of the loading machine to assist movement of the bucket assembly into the pile of material.

- United States Patent 1191 Kamner Dec. 17, 1974 [54] TRACTION ASSIST MEANS FOR LOADING 3,345,108 10/1967 Newman 299/31 MACHINES AND THE LIKE R b G Sh d Primary Examiner 0 ert eri an Inventor: Ha1m J. Kamner, Palatme, Ill. Assistant Examiner john Mannix [73] Assignee: Goodman Equipment Corporation, A rn y, g 0r FirmFitCh, Even, Tabin &

- Chicago, Ill. Luedeka v [22] Filed: Dec. 18, 1972 [57] ABSTRACT PP 316,406 A loading machine is' disclosed having a main frame, a forward swing frame pivotally mounted on the main 52 US. Cl. 214/140 180/8 BA 214/145 frame a loading bucket assembly Supported [51 1 Int CL." 3 9/00 swing frame for movement to'pick up and dump loose [58] Field of Search /73 material onto the swing frame, and traction assist 105/31, 214/ 1 A 6 R means movable to a ground engaging position in a 299/67 manner to prevent rearward movement of the loading machine as the bucket assembly is moved forwardly [56] References Cited into a pile of loose material and to stabilize the machine as the bucket is raised to a dumping position. UNITED STATES PATENTS The traction assist means is further operative to effect 2 Biedess .l R a forward movement of the loading machine to assist 3 g' movement of the bucket assembly into the pile of maerno 21S 3 081,891 3/1963 Przybylski. 214/131 A tel-la]. 3 161,306 12/1964 Granryd 214/145 11 Claims, 5 Drawing Figures PATENT EECI 7 i974 SHEET 10F a PAH-INTEL EEC] H974 SHEET 2 [IF 4 1 TRACTION AssIsT MEANS FOR LOADING MACHINES AND THE LIKE The present invention relates generally to loading machines and the like, and more particularly to traction assist means operative to assist in loading and stabilizing of a loading machine during operation.

It is a conventional practice in mining operations, both above ground open face mining and below ground tunnel mining, to employ loading machines having means such as bucket assemblies on their forward ends which are operative to load loose material onto the machines from piles disposed forwardly of and on both sides of the machines. Such loading machines frequently have conveyor means for transferring the loose material to an elevated position where it is deposited into hauling vehicles. In the mining industry, these loading machines are commonly termed muckers and include main frames which are movable along the ground, such as on tracks, to a position generally adjacent a face wall to be mined. The muckers have bucket assemblies or similar means mounted on forward swing frames which are, in turn, mounted on the main frame for pivotal movement about both horizontal and vertical axes relative to the main frame.'A bucket assembly is first moved to a lowered position adjacent-a pile of loose material, then advanced into the pile of material by crowding and rooting." Crowding" is conventionally accomplished by tramming the machine forward, while rooting" is generally accomplished by jiggling or rocking the bucket assembly slightly. After loading loose material into the bucket during its advancing or crowding movement, the bucket assembly is raised to an elevated position to dump the load onto a conveyor mounted on the swing frame whereupon the loose material is transferred onto a conveyor mounted on the main frame from which it is loaded into hauling vehicles. A loading machine of this general type is dis? closed in my copending application, Ser. No. 105,904, filed Jan. 12, 1971.

It will be appreciated that loading machines of the aforedescribed type frequently load relatively large size pieces of material which may approach up to two .tons in weight. Loading material heavy such significant particle size requires relatively large loading machines and, accordingly, requires substantial forces to advance the loading buckets into piles of material and thereafter raise the loaded buckets to dumping positions. The reaction forces created by resistance of a pile of loose material to forward movement of the shovel or bucket assembly on a loading machine often tend to move the loading machine slightly rearwardly away from the pile of loose material. Additionally, the forces required to break-out or shear portions of rock material from interlocking rocks in a pile of material being loaded and the eavy loads handled by the bucket assemblies create stability problems as the bucket assemblies are moved to elevated dumping positions.

The present invention is directed to traction assist means for use with a loading machine and the like' to prevent rearward movement of the associated loading I forassisting in forward movement of the loading machine to provide additional movement of-the bucket assembly into the pile of loose material. A

Accordingly, one of the primary objects of the present invention is to provide novel traction assist means for use with a loading machine and the like to resist rearward movement of the machine as loading means onthe forward end of the machine is advanced forwardly into a pile of material tov be loaded.

, Another object of the present invention is to provide novel traction assist means for use with a mining machine and the like to assist in advancing the machine during a loading operation and to provide stability for the machine during operation.

Still another object of thepresent invention is to provide novel traction assist meansfor use with a loading machine and the like having loading means thereon, wherein the traction assist means includes at least one ground-engaging'member and operating means for effecting movement of the member to a ground engaging position in a manner to resist rearward movement of the machine as the loading means is advanced into a pile of material to be loaded.

Another object of the present invention is to provide novel traction assist means for use with a loading machine and the like, having a loading bucket assembly on its forward end, wherein the tractionassist means includes a ground-engaging leg member movable to effect forward advancing movement of the loading machine simultaneously with a primary movement of the bucket assembly intoa pile of loosematerial for loading the. same. Yet another object of the present invention is to provide traction assist means as described wherein novel means interconnect the ground-engaging leg'member to operating clyinders for the bucket assembly in a manner to provide sufficient energy for moving the leg member to a ground-engagingposition to resist'rearward movement of the loading machine as the bucket assembly is advanced into a pile of loose material, the interconnecting means being adapted to maintain the leg member in ground-engaging position while'providing maximum energy from the operating cylinders to move the bucket assembly to an elevated load dumping position.

Still another object of the present invention is to provide novel traction assist means as described wherein the ground-engaging leg member is movable to a nesting position with the bucket assembly when the bucket assembly is in its lowered position preparatory to being advanced into a pile of loose material.

Further objects and advantages of the present inveneration thereof, will become apparent from the following detailed description of the invention when taken in machine as the bucket assembly thereon is advanced into a pile of loose material to be loaded, and also to stabilize the loading machine and provide maximum energy for movement of the associated bucket assembly to an elevated dumping position. The traction assist means of the present invention further provides means conjunction with the accompanying drawings wherein like reference numerals designate like elements throughout the several views, and wherein:

' FIG. 1 is a partial side elevational view ofa loading machine employing traction assist means in accordance taken substantially along arm and its associated cam groove.

Referring now to the drawings, the present invention is illustrated, by way of example, as being employed on a loading machine as partially shown at 10. The loading machine is of the type commercially available from the assignee of the present invention and finds particular application in the mining industry in accordance with a general process wherein material such as rock is periodically drilled and blasted from the face of an excavation, as in an underground tunnel mine, to form a relatively large pile of loose rock, such as indicated at 12, which is to be loaded by the loading machine 10 into hauling cars (not shown) and the like.

The loading machine 10 includes mobile frame means comprising a main frame or chassis, indicated generally at 14, and forward swing frame means, indicated generally at 16, mounted on the main frame 14 for pivotal movement about both vertical and horizontal axes relative to the main frame. The forward swing The main frame or chassis 14 has track-engaging wheels, one of which is shown at 24, and drive means (not shown) for driving the wheels 24 along rails 26 as may be provided on the ground surface 23 in a tunnel dinally along the beams 38 on opposite sides of the conveyor belt 32 and define passage or channel means therebetween-along which the loaded loose material may pass during movement on the conveyor belt 32.

The main frame 14 also has laterally spaced upstanding side panels 42 disposed on opposite sides of the conveyor belt 36 to define channel or passage means on the main frame 14 through which the material is conveyed to the awaiting'hauling cars.

-A pair of double-acting fluid actuating cylinders, one of which is shown at 44, are mounted between the main frame 14 and the pivot frame 18 and are operative in a known manner to effect pivotal movement of the pivot frame 18 about a vertical axis relative to the main frame. A double-acting fluid actuating cylinder 46 is mounted on the pivot frame 18 and has an extendible piston end pivotally connected to the conveyor boom 20 to effect selective pivotal movement of the conveyor under process of construction. The loading machine 10 is selectively movable along the rails 26 to a position generally adjacent the pile of loose material 12, which has been drilled and blasted from the face of the excavation for purposes of loading the loose material 12 onto the loading machine 10 for transfer to hauling cars as is generally known.

The conveyor boom 20 of the forward swing frame means 16 has a bucket or shovel assembly, indicated generally at 30, supported on its'forward end. The bucket assembly 30 is movable with the conveyor boom 20 to a position adjacent the pile of loose material 12 and is operable to load the loose material onto an endless belt conveyor 32 mounted on the conveyor boom 20 such that the material is moved rearwardly on the conveyor boom and is deposited onto a downwardly inclined pan plate 34 mounted on the pivot frame 18. The loose material deposited onto the pan plate 34 moves downwardly thereon and is deposited onto the lower forward end of an upwardly inclined endless conveyor belt 36 mounted on the main frame 14 whereupon the material is conveyed to an elevated position rearwardly of the main frame for deposit into hauling cars or vehicles (not shown).

shovel element, indicated generally at 50. The receptai cle element 48 has aback wall 52 and parallel side' walls 54 which are pivotally supported on a horizontal pivot shaft 56 mounted on and between the forward ends of a pair of laterally spaced, vertically upstanding support plate brackets 58 secured to the beams 38 of the conveyor boom 20. The shovel element has a.

blade-like bottom wall 60 and parallel side walls 62 spaced slightly laterally outwardly of the parallel walls 54 of the receptacle element 48. The receptacle element 48 and shovel elementSO are pivotally connected through pivot pin connections 64 to permit pivotal extension and retraction of the shovel element 50 relative to the receptacle element 48, extension of the shovel element being limited by cooperating stops 66 and 68 on the receptacle element 48 and shovel element 50, respectively. V The mechanism for effecting operating movement of the bucket assembly 30 relative to the conveyor boom 20 to advance the shovel element 50 into the pile of loose material 12 and thereafter elevate the bucket assembly to a dumping position comprises a pair of double-acting fluid cylinders 70 mounted on opposite sides of the conveyor boom 20. Each of the cylinders 70 has a pivotal connection at 72 to an associated one of the support plate brackets 58. Suitable spacer blocks, indiend of a swing arm or bell crank which is pivotally The forward conveyor boom 20 includes a pair of spaced upstanding side panels 40 are mounted longitumounted at 82 between the associated support plate bracket 58 and the beam 38 of the conveyor boom 20. V

The end of each of the swing arms 80 opposite its pivota'l connection 78 is pivotally connected at 84 to one end of an adjustable length linkage 86 which has its opposite end pivotally connected at 88 to an associated one of the side walls 54 of the receptacle element 48.

The shovel element 50 is pivotallyconnected through a pair of pivot pins 90 to a pair of laterally spaced double acting fluid actuating cylinders 92 each of which has an extendible piston 94 pivotally connected to the forward end of the associated beam 38 through a pivot connection 96. The piston 94 of each of the fluid actuating cylinders 92 is normally maintained in a retracted position such that the actuating cylinders 92 function as fixed length links generally paralleling lines drawn between the pivot axes 56 and 64. In this manner, when the main fluid cylinders 70 are energized during forward advancing movement of the bucket assembly 30, the shovel element 50 will extend from its retracted position within the receptacle element 48 in a generally straightline forward advancing movement into the pile of loose material 12, as described more fully in my referenced copending application, Ser. No. 105,904. After the bucket assembly 30 has been loaded with loose material, the pistons 76 of the main actuating cylinders 70 are extended further to effect upward pivotal movement of the bucket assembly 30 about the pivot axis 56 to an elevated dumping position as shown in FIG. 3. The actuating cylinders 92 may then be energized to extend their associated pistons 74 to retract the shovel element 50 into the receptacle element 48 and assist in discharging material from theshovel element.

It will be appreciated that when the bucket assembly 30 is advanced into a pile of loose material, such as indicated at 12, from a position adjacent the pile of material upon energizing the main actuating cylinders 70,

the pile of material offers resistance to advancingmovement of the bucket assembly resulting in reaction forces which tend to move the loading machine rearwardly in a direction away from the pile of material. The present invention is directed to traction assist means, indicated generally at 100, for use in combination with a loading machine 10 and the like, the traction assist means being selectively movable to a ground engaging position in a manner to resist any forces tending to move the loading machine away from the pile of material 12 to be loaded as the bucket assembly 30 is advanced into the pile of material through energizing the main actuating cylinders 70.

The traction assist means 100 in accordance with the present invention is also adapted for-movement to maintain a ground engaging position and stabilize the loading machine 10 throughout movement of the bucket assembly 30 from its lowered position to its advanced position and then to an elevated dumping position during a loading cycle. Additionally, the traction assist means 100 in accordance with the present inventube 106. The radial arms 108 are pivotally connectedto and supported by axially aligned support pins 110 secured withininverted U-shaped support brackets 112 secured to the lowersurfaces of the beams 38 of the conveyor boom 20, as best seen in FIG. 4. A pair of angularly disposed support braces 114 are secured between the depending ground-engaging leg member 102 and the laterally spaced radial arms 108 to provide rigid support for the ground-engaging leg member.

IA pair of radial control arms 116 are fixedly secured on the opposite ends of the support tube 106 and lie in planes perpendicular to the longitudinal axis of the support tube. Each of the control arms 116 has a cylindrical boss shaped cam follower 118' secured thereon so as to extend outwardly from the outer surface of the corresponding control arm. Each of the cam followers 118 is slidingly received within a cam groove 120 formed in the inner surface of the associated swing arm 80, as best seen in FIGS. 2 and 3.

With reference to FIG. 5, the cam groove 120 in each of the swing arms 80 is of sufficient size to maintain sliding relation with the associated cam follower 118 g and includes a first cam section'or portion indicated by the included'angle alpha which serves as the rise portion of the cam groove, anda second cam section or portion indicated by the included angle beta which comprises a dwell portion of the cam groove 120. In

one embodiment of the traction assist means 100, the

of the swing arms 80 when the bucket assemblyactuating cylinders 70 are energized asdescribed more fully below. The swing arms 80' thus comprise swing arm means which include control cam means in the form of the cam grooves 120 for cooperation with the cam followers 1 18 on the associated control arms 1 16 to effect selective movement of the ground-engaging leg member 102. Y

The elements comprising the traction assist means 100 have configurations which establish a nesting relation of the ground-engaging leg memberl02 with the bucket assembly 30 when the bucket assembly is in a retracted or downward pivotal position relative to the conveyor boom 20, as when the primary actuating cylinders 70 are in fully retracted positions. With the Y bucket assembly 30 and traction assist means 100 in pending spurs 104 suitably secured to the lower end thereof as shown in FIG. 1. The ground-engaging leg member 102 is fixedly secured to the longitudinal center of a transverse support tube 106. The support tube 106 has a pair of radial arms 108 fixedly secured thereon slightly inwardly from the opposite ends of the such nested relation, the operator may move the conveyor boom 20 through actuation of the cylinders 44 and 46m a position wherein the bucket assembly is lowered adjacent the pile of loose material 12, such as fly-rock, to be loaded. The bucket assembly 30 and traction assist means 100 are shown in their nested lowered positions in phantom in FIG. 2. Energizing the primary actuating cylinders serves to effect forward movement of the shovel element50 outwardly from the receptacle element 48 as the receptacle element is pivoted upwardly about its pivot axis 56 whereby to effect advancing movement of the shovel element into the pile of material 12. v

As the primary actuating cylinders 70 are initially energized or actuated to effect pivotal movement of the swing arms 80, the ground-engaging leg member 102 of the traction assist means 100 is moved to a position engaging the ground surface 28 underlying the longitudinal axis of the conveyor boom 20 such that one or more of the spurs 106 digs into the ground, depending upon the hardness of the ground. The rise or power portions alpha of the cam grooves 120 are effective to cause the ground-engaging leg member 102 to kick down into ground engaging relation almost immediately after energizing the primary cylinders 70, with a simultaneous forward straight-line movement of the shovel element 50 into the pile of material '12. The rise portions alpha of the cam grooves 120 are such that a substantial portion of the energy from the actuating cylinders 70 is transferred to the control arms 116 to move the ground-engaging leg member l02to its maximum downward pivotal position relative to the conveyor boom 20 as the shovel element 50 is fully advanced into the pile of material 12. By effecting engagement of the spurs 106 with the ground surface 28 througha clockwise rotation of the leg member 102, as

considered in FIG. 2, it can be seen that the leg member 102 establishes a reaction force with the ground 28 to resist the aforedescribed reaction forces established by resistance of the pile of material to entry of the shovel element 50 thereinto. in this manner, rearward movement of the loading machine under the influence of the aforenoted reaction forces is resisted and prevented by the traction assist means 100.

After the spurs 106 initially engage-the ground 28 during downward pivotal movement of the leg member 102, continued downward movement of the leg member throughout the latter portion of travel of th'ecam followers 118 within the cam groove rise or power portions alpha will cause the loading machine to move forwardly toward the pile of material with the point of contact of the leg member 102 with the ground serving as a reaction point. The loading machine 10 is thus caused to move forwardly in a direction toward the pile of loose material 12, resulting in further forward movement or crowding of the shovel element 50 into the pile of material. The forward movement of the loading machine 10 caused by the traction assist means 100 is' I partially illustrated in FIG. 2 by the leg member 102 being shown in an initial position in phantom, and in a fully depressedvposition in solid lines.

As the actuating cylinders 70 are further energized to effect upward pivotal movement of the bucket assembly 30 toward an elevated dumping position, as illustrated in H6. 3, the cam followers 118 are disposed within the dwell portions beta of their respective cam grooves 120 such that the ground-engaging leg member 102 remains in a stationary ground engaging position. As the bucket assembly 30 initially begins its upwardmovement relative to the ground, relatively large break-out or shear forces are required to establish shear planes in large rocks which are interlocked 1 with other rocks in the pile of rock or similar material being loaded. .By providing the dwell portions beta in the cam grooves 120 for cooperation with the cam followers 118 when the bucket assembly 30 is moved upwardly to break out rocks from the pile 12,. substantially all of the energy from the cylinders 70 is transferred to the shovel element 50 to provide maximum energy for breaking out" the bucket assembly with a load therein. The continued ground engaging position of the leg member 102 serves to provide stability for 10, asthe bucket assembly 30 is broken out from the pile l2 and raised to its elevated dumping position. After dumping the contents from the bucket assembly 30, the actuating cylinders 70 are retracted to effect downward pivotal movement of the bucket assembly. Simultaneous with such downward pivotal'movement of the bucket assembly preparatory to the next loading cycle, the ground-engaging leg member 102 will remain in ground engaging relation until the cam followers 118 again are disposed within the rise" portions alpha of the respective cam grooves 120. During reverse pivotal movement of the swing arms 80 with the cam followers 118 within the cam groove portions alpha, the leg member 102 is retracted upwardly simultaneously with retraction of the shovel assembly 30 to effect nesting relation of the ground-engaging leg member 102 with the bucket assembly 30 as aforedescribed.

Having thus described a preferred embodiment of the traction assist means 100 in accordance with the present invention, it can be seen that the present invention has provided means which resist rearward movement of a loading machine as loading means, such as a bucket assembly 30 on the forwardend of the conveyor boom 20, is actuated to effect advancing movement of the bucket assembly into a pile of loose material to be loaded. Additionally, the traction assist means 100 in accordance with the present invention provides stabilizing means for the loading machine, and particularly the conveyor boom 20, during movement of the bucket assembly 30' to an elevated dumping position after loading material into the shovel element 50, while simultaneously providing maximum energy transferfrom ment of the bucket assembly during loading-of material into the shovel element 50, thereby increasing the efficiency of the loading operation. Still further, the nesting capabilities of the ground-engaging l'eg member-102 of the traction assist means 100 with the bucket assembly 30 provides a compact assembly'which is readily maneuverable to positions adjacent piles'of, material disposed forwardly of or on either lateral side of the I loading machine 10, and thus facilitates greater loading capabilities for the loading machine 10.

While the present invention has been described in conjunction with a loading machine as generally employed in the mining industry, it will be understood that the traction assist means 100 may find application with other machines of the general type described wherein means are provided on the forward end of the machine for digging or working a surface where reaction forces are created which tend to move the machine rearwardly in opposition to forward movement of the digging or working means. It will also be understood that more than one ground-engaging leg. member 102 may be securedonto the transverse support tube 106.

Thus, while a preferred embodiment of the present invention has been illustrated and described, it will be understood to those skilled in the art that changes and means and swing arm means operatively associated with said bucket means to effect movement thereof, said swing arm means including cont-rol cam means, and said second operating means including a control arm connected to said ground-engagingmember and having acam follower cooperative with said control cam means to effect simultaneous movement of said ground-engaging member upon actuation of said swing of material to an advanced position into the pile of material to load said bucket means, and thereafter to an elevated position effective to dump said material from said bucket means onto said frame means, first operating means including actuating cylinder means and swing arm means cooperative with said bucket means to effect said movement thereof, and traction assist means including at least one ground engaging member supported by said frame means rearwardly from and independently of said support of said bucket means by said frame means, and second operating means operatively associated with said actuating cylinder means in a manner to move said ground-engaging member to a ground engaging position and effect movement of said frame means toward the pile of material as said bucket first operating means, said second operating means being further operative to maintain said ground engaging member in said ground engaging position throughout movement of said bucket means from its lowered position to its said elevated position so as to stabilize said frame means during a loading cycle.

2. A loading machine as defined in claim 1 wherein said traction assist means comprises a single leg mem ber adapted for nesting relation with said bucket means when said bucket means is disposed in'its said lowered position, said leg member being selectively movable to engage the ground underlying the longitudinal axis of said bucket means.

3. A loading machine as defined in claim 1 wherein said frame means includes a main frame and a swing frame supported on said main frame for pivotal movement about horizontal and vertical axes relative to said main frame, said bucket means and said traction assist means being supported on said swing frame for pivotal movement therewith.

4. A loading machine comprising, in combination, frame means movable along a ground surface to a position generally. adjacent a pile of loose material to be loaded, bucket means supported by said frame means for movement from a lowered position adjacent the pile of material to an advanced position into the pile of ma-' terial to .load said bucket means, and thereafter to an elevated position effective to dump said-material from said bucket means onto said frame means, first operat ing means cooperative with said bucket means to effect said movement thereof, and traction assist means including at least one groundengaging member sup-' ported by said frame means and movable to a ground engaging position, said traction assist means further in-. cluding second operating means operative to effect ground engagement of said ground-engaging member in a manner to resist any forces tending to move said frame means away from the pile of material throughout movement of said bucket means from its lowered position to its said elevated position during a loading cycle,

said first operating means including actuating cylinder arm means.

, 5. A loading machine as defined in claim 4 wherein said control cam means comprises at least one cam groove having afirst portion adapted to effect movement of said ground-engaging member to its said ground-engaging position when said bucket means is moved to'its said advanced position, said cam groove having a second dwell portion adapted to maintain said ground-engaging member in a relatively stationary ground engaging position during movement of said bucket means from its said advanced position to its said elevated position.

6. A loading machine as defined in claim 5 wherein said first'portion of said cam groove is adapted to effect movement of said ground-engaging member in a direction to effect movement of said frame means toward, the pile of materialto be loaded when said bucket means is moved to its said advanced position.

7. In a loading machine having mobile framemeans adapted to be moved into position generally adjacent a pile of loose material to be loaded, bucket means mounted on said frame means for movement from a said bucket means when said bucket means is'disposed in its said lowered position, second operating means for effecting movement of said ground-engaging means to said ground engaging position in a manner to resist forces tending to move said frame means away from the pile of material as said bucket means is advanced into the pile of material, said second-operating means being directly responsive to actuation of said first operating means to effect movement of said leg member to said ground engaging position upon movement of said bucket means to its said advanced position into the pile of material.

8. The improvement of claim 7 wherein said groundengaging means comprises a single leg member adapted to engage the ground underlying the longitudinal axis of said bucket means when said leg member is moved to said ground engaging position.

9. The improvement as defined in claim 7 wherein said first operating means includes actuating cylinder means operatively associated with said bucket means to effect said movement of said bucket means, and

' wherein said second operating means is operatively associated with said actuating cylinder means in a manner to effect movement of said ground-engaging means to said ground engaging position simultaneously with movement of said bucket means to its said advanced position.

10. In a loading machine having mobile frame means adapted to be moved into position generally adjacent a pile of loose material to be loaded,'bucket means mounted on said frame means for movement from a lowered position adjacent the pile of material to an advanced position into the pile of material toload material into said bucket means, and thereafter to an elevated position effective to dump material from said bucket means onto said frame means, and first operating means including actuating cylinder means operatively associated with said bucket means for effecting said movement of said bucket means; the improvement therewith comprising, in combination, traction assist means including ground-engaging means supported by said frame means for movement to a ground engaging position when said bucket means is advanced from its said lowered position to its said advanced position, and second operating means operatively associated with said actuating cylinder means and including control cam means operative upon actuation of said cylinder means to effect said movement of said ground-engaging means to its said vground engaging position simultaneously with movement of said bucket means to its said advanced position, said control .cam means being further operative to raise said ground-engaging means for nesting relation with said bucket means when said bucket means is moved-to its said lowered position from its said elevated position after dumping material from said bucket means onto said frame means.

11. The improvement as defined in claim 10 wherein said control cam means is adapted to operatively interconnect said actuating cylindermeans to said groundengaging means, said control cam means comprising at least one cam groove having a first cam portion adapted to transfer sufficient energy from said actuating cylinder means to said ground-engaging means to move said ground-engaging means to said ground engaging position when said bucket means is advanced to its said advanced position, said cam'. groove having a second cam portion adapted to mtaintain said groundengaging means in said ground engaging position while providing maximum transfer of energy from said actuating cylinder means to said bucket means for moving said bucket means to its said elevated position. 

1. A loading machine comprising, in combination, frame means movable along a ground surface to a position generally adjacent a pile of loose material to be loaded, bucket means supported by said frame means for movement from a lowered position adjacent the pile of material to an advanced position into the pile of material to load said bucket means, and thereafter to an elevated position effective to dump said material from said bucket means onto said frame means, first operating means including actuating cylinder means and swing arm means cooperative with said bucket means to effect said movement thereof, and traction assist means including at least one ground engaging member supported by said frame means rearwardly from and independently of said support of said bucket means by said frame means, and second operating means operatively associated with said actuating cylinder means in a manner to move said ground-engaging member to a ground engaging position and effect movement of said frame means toward the pile of material as said bucket means is moved to its said advanced position by said first operating means, said second operating means being further operative to maintain said ground-engaging member in said ground engaging position throughout movement of said bucket means from its lowered position to its said elevated position so as to stabilize said frame means during a loading cycle.
 2. A loading machine as defined in claim 1 wherein said traction assist means comprises a single leg member adapted for nesting relation with said bucket means when said bucket means is disposed in its said lowered position, said leg member being selectively movable to engage the ground underlying the longitudinal axis of said bucket means.
 3. A loading machine as defined in claim 1 wherein said frame means includes a main frame and a swing frame supported on said main frame for pivotal movement about horizontal and vertical axes relative to said main frame, said bucket means and said traction assist means being supported on said swing frame for pivotal movement therewith.
 4. A loading machine comprising, in combination, frame means movable along a ground surface to a position generally adjacent a pile of loose material to be loaded, bucket means supported by said frame means for movement from a lowered position adjacent the pile of material to an advanced position into the pile of material to load said bucket means, and thereafter to an elevated position effective to dump said material from said bucket means onto said frame means, first operating means cooperative with said bucket means to effect said movement thereof, and traction assist means including at least one ground-engaging member supported by said frame means and movable to a ground engaging position, said traction assist means further including second operating means opeRative to effect ground engagement of said ground-engaging member in a manner to resist any forces tending to move said frame means away from the pile of material throughout movement of said bucket means from its lowered position to its said elevated position during a loading cycle, said first operating means including actuating cylinder means and swing arm means operatively associated with said bucket means to effect movement thereof, said swing arm means including control cam means, and said second operating means including a control arm connected to said ground-engaging member and having a cam follower cooperative with said control cam means to effect simultaneous movement of said ground-engaging member upon actuation of said swing arm means.
 5. A loading machine as defined in claim 4 wherein said control cam means comprises at least one cam groove having a first portion adapted to effect movement of said ground-engaging member to its said ground engaging position when said bucket means is moved to its said advanced position, said cam groove having a second dwell portion adapted to maintain said ground-engaging member in a relatively stationary ground engaging position during movement of said bucket means from its said advanced position to its said elevated position.
 6. A loading machine as defined in claim 5 wherein said first portion of said cam groove is adapted to effect movement of said ground-engaging member in a direction to effect movement of said frame means toward the pile of material to be loaded when said bucket means is moved to its said advanced position.
 7. In a loading machine having mobile frame means adapted to be moved into position generally adjacent a pile of loose material to be loaded, bucket means mounted on said frame means for movement from a lowered position adjacent the pile of material to an advanced position into the pile of material to load material into said bucket means, and thereafter to an elevated position effective to dump material from said bucket means onto said frame means, and first operating means for effecting said movement of said bucket means; the improvement therewith comprising, in combination, traction assist means including ground-engaging means having at least one leg member directly supported by said frame means for nesting relation with said bucket means when said bucket means is disposed in its said lowered position, second operating means for effecting movement of said ground-engaging means to said ground engaging position in a manner to resist forces tending to move said frame means away from the pile of material as said bucket means is advanced into the pile of material, said second operating means being directly responsive to actuation of said first operating means to effect movement of said leg member to said ground engaging position upon movement of said bucket means to its said advanced position into the pile of material.
 8. The improvement of claim 7 wherein said ground-engaging means comprises a single leg member adapted to engage the ground underlying the longitudinal axis of said bucket means when said leg member is moved to said ground engaging position.
 9. The improvement as defined in claim 7 wherein said first operating means includes actuating cylinder means operatively associated with said bucket means to effect said movement of said bucket means, and wherein said second operating means is operatively associated with said actuating cylinder means in a manner to effect movement of said ground-engaging means to said ground engaging position simultaneously with movement of said bucket means to its said advanced position.
 10. In a loading machine having mobile frame means adapted to be moved into position generally adjacent a pile of loose material to be loaded, bucket means mounted on said frame means for movement from a lowered position adjacent the pile of material to an advanced position into the pile of material to load material into said bucket means, and thereafter to an elevated poSition effective to dump material from said bucket means onto said frame means, and first operating means including actuating cylinder means operatively associated with said bucket means for effecting said movement of said bucket means; the improvement therewith comprising, in combination, traction assist means including ground-engaging means supported by said frame means for movement to a ground engaging position when said bucket means is advanced from its said lowered position to its said advanced position, and second operating means operatively associated with said actuating cylinder means and including control cam means operative upon actuation of said cylinder means to effect said movement of said ground-engaging means to its said ground engaging position simultaneously with movement of said bucket means to its said advanced position, said control cam means being further operative to raise said ground-engaging means for nesting relation with said bucket means when said bucket means is moved to its said lowered position from its said elevated position after dumping material from said bucket means onto said frame means.
 11. The improvement as defined in claim 10 wherein said control cam means is adapted to operatively interconnect said actuating cylinder means to said ground-engaging means, said control cam means comprising at least one cam groove having a first cam portion adapted to transfer sufficient energy from said actuating cylinder means to said ground-engaging means to move said ground-engaging means to said ground engaging position when said bucket means is advanced to its said advanced position, said cam groove having a second cam portion adapted to mtaintain said ground-engaging means in said ground engaging position while providing maximum transfer of energy from said actuating cylinder means to said bucket means for moving said bucket means to its said elevated position. 